Fossil Find New Branch in Human Family Tree?

Where do we come from? That's often the first question a child asks and it has bedevilled scientists for centuries. Well, today we're a little bit closer to answering it.

This past Thursday it was announced - with great fanfare - that the remains of a nine-year-old boy were found in South Africa. He is almost two million years old.

He's being called "Sediba," which means "source," and he stands somewhere on the road between ape and human. He lived in a period when our ancestors climbed down from the trees and started living on the ground. He belongs to a previously unidentified species and anthropologists will be studying him for decades.

Before the announcement, "60 Minutes" and correspondent Bob Simon were given rare access to the discovery, which could be among the most important of our time.

His unveiling was a major happening this past Thursday, when he appeared at a press conference in Johannesburg.

Professor Lee Berger, an American paleoanthropologist at the University of the Witwatersrand, named him Australopithecus sediba. And the most astonishing thing about him is his skull: 1.9 million years old and so well preserved that you can count his teeth - so very much like ours.

Where did Sediba live? In hills just 50 minutes from Johannesburg, in what is called the "Cradle of Human Kind." After all, we humans came from Africa. And scientists there have spent the better part of a century looking for fragments of our earliest ancestors.

"There's probably nowhere else on planet Earth that has a denser, better record of human origins than this land right here," Berger explained.

Yet Berger had been searching for fossils in caves here for years and hadn't found much of anything. So he started a mapping project using a very modern tool: Google Earth. He discovered some 500 caves in the region, which no scientists had ever explored.

"And then I started walking. And I walked a lot. Hundreds of kilometres," he explained.

Berger was walking through the Malapa Nature Reserve with his trusted dog Tau, his nine-year-old son Matthew and his colleague Job Kibii.

They came across a cave and that was the beginning of an astonishing series of events.

"I...literally said, you know, 'Here's the site. There are bones here. Let's look around.' Matthew got up, ran over in that direction. A minute and a half later, he called me," Berger remembered.